Incrementally-tapered bobbins

ABSTRACT

A textile yarn support, such as a hollow impregnated-paper tubular bobbin having a slight overall taper inwardly from bottom to tip, has a &#39;&#39;&#39;&#39;stepped&#39;&#39;&#39;&#39; external configuration brought about by progressive small reductions in external diameter, by the same amount, of successive adjoining shortlength sections thereof, all of such sections having substantially the same uniform taper, and the relatively abrupt changes from maximum diameter of one section to minimum diameter of the next adjoining section being of less annular width than the diameter of yarn intended to be wound upon the bobbin, thereby promoting uniform and controlled high-speed winding and unwinding of yarn and facilitating clean stripping of waste.

United States Patent 1 Adams et al.

[ 1 INC REMENTALLY-TAPERED BOBBINS FOREIGN PATENTS OR APPLICATIONS9/1953 United Kingdom 242/118.3

1 June 17, 1975 716,036 9/1954 United Kingdom 242/118.3

Primary Examiner-George F. Mautz Attorney, Agent, or Firm-James E. Mrose57 ABSTRACT A textile yarn support, such as a hollow impregnatedpapertubular bobbin having a slight overall taper inwardly from bottom totip, has a stepped" external configuration brought about by progressivesmall reductions in external diameter, by the same amount, of successiveadjoining shortlength sections thereof, all of such sections havingsubstantially the same uniform taper, and the relatively abrupt changesfrom maximum diameter of one section to minimum diameter of the nextadjoining section being of less annular width than the diameter of yarnintended to be wound upon the bobbin, thereby promoting uniform andcontrolled high-speed winding and unwinding of yarn and facilitatingclean stripping of waste.

1 Claim, 3 Drawing Figures 1 INCREMENTALLY-TAPERED BOBBINS BACKGROUND OFTHE INVENTION The present invention relates to improvements in supportsor carriers for textile yarn and like materials which are to be woundand unwound at high speeds without undue hazard of breakage such as maybe induced by imprecise and irregular package build-up, and, in oneparticular aspect, to novel and improved bobbins the exteriors of whichare incrementally rather than uniformly tapered, to form unique shallowsteps, each of lesser depth than the diameter of yarns with which theyare to be used, which will promote controlled and firmly-heldemplacement of windings and yet will facilitate waste-removaloperations.

As is well known in the textile machinery art, packages of yarn or othertextile threads are commonly collected upon spindle-mounted cores orbobbins for further processing and dispensing, it being important thatsuch bobbins be of predetermined external dimensions and have relativelysmooth surface characteristics, that they be of relatively light weightand inexpensive, and that they lend themselves to collection and removalof yarn at very high rates without developing excessive numbers ofso-called ends down (i.e., yarn breakages), slippage, shifts inposition, sloughing and tangling. The bobbin and spindle assemblieswhich have been evolved over the course of many years in thiswelldeveloped art have assumed a variety of structural forms and havebeen fabricated of many different materials; however, the type of bobbinto which the present invention is particularly directed involves ahollow tubular element which may be slightly tapered, or coniCally-sloped, and which may typically be made of impregnated paper,plastic, or the like. Such bobbins are generally intended to be matedrather loosely with spindles over substantially their full lengths andare slipfitted in frictionally-driven relationships with uprightspindles near their upper ends. Large numbers of these bobbins aredropped, empty, onto the numerous upstanding spindles of a windingmachine, after a few turns have first been wrapped manually orautomatically around the base or acorn portion of each of the spindles,and the spindles are then rapidly accelerated to the very highrotational speeds which are modernly required for heightenedproductivity. Package build-up on each bobbin is conventionallyregulated by a surrounding movable ring-traveller, which is designed tohave the yarn pulled through it at an optimum angle for reduction ofbreakage possibilities.

Because even slight surface irregularities on bobbins can tend todisturb the yarn and cause occurrence of troublesome and costly endsdown conditions, it has commonly been accepted that the external profileof a bobbin should be essentially straight along its package build-upregion (i.e., essentially its full length). A notable exception appearsin the case of the usual circumferential ring-like grooves orcorrugations, which are distributed along the bobbin exterior, and areintended to anchor certain spaced portions of the yarn wrapped next tothe bobbin surface and thereby ultimately secure the entire yarn packageagainst axial slippage. If such grooves are too shallow, they are unableto serve the intended function, and, if of sufficient depth for suchpurposes, can become an unintended serious contributor topoorly-controlled formation of the yarn package and to yarn breakage andto waste-removal problems. Once the yarn packages commence build-up inan imperfectly-controlled manner, all subsequent operations, includingdyeing and finishing, can be adversely affected; if yarn breakage doesnot actually occur, for example, the irregular tensioning and slackingof yarn, or tangling, can lead to such difficulties. In part, problemsassociated with conventional grooves or corrugations are thought to stemfrom unintended embedment or trapping of multiple turns of yarn insingle grooves designed to accommodate only one turn; this is acondition which tends to arise as the normal relaxed thickness of theyarn is compressed to about half that amount under accompanying windingtension. As the usual traveller ring is raised and lowered alternatelyduring initial winding, the tensed yarn, several wraps can fall withinthe contours of the grooves, and the initial build-up becomes uneven;such unevenness in turn occasions irregularities in the package as itdevelops, and the roots of the aforementioned problems are then wellestablished. Specifically, the yarn may be sometimes tense and sometimesrelatively slack, tangles are more likely to occur, breakage risks areheightened, and ultimate removal of waste is more difficult because oftight yarn entrapments in the grooves.

Bobbins of the type which may be improved through practice of thepresent invention appear in U.S. Pat. Nos. 3,321,901 and 3,167,262.

SUMMARY In accordance with the present teachings, difficulties of theaforesaid character can be very greatly reduced, with the relatedstructural innovations being remarkably simple and inexpensive. Theseinnovations are concerned with elimination of the usual external groovesor corrugations of a bobbin, and the substitution, instead, of numerousrelatively shallow uniformlysloped steps distributed along the length ofthe bobbin exterior, each such step forming a riser with its neighborwhich is of lesser height than the uncompressed diameter of the yarn tobe used, and the pro jecting ends of the steps being aligned to form asub-' stantially linear overall profile for the bobbin.

It is one of the objects of the present invention to provide novel andimproved textile bobbins, and the like, in which inexpensivereadily-shaped, and uncomplicated external surface contouring promotescontrolled uniform yarn-package build-up, suppresses breakage tendenciesand unwinding irregularities, and facilitates waste removals.

A further object is to provide unique incrementallytapered textilebobbins having stepped rather than grooved or corrugated exteriorsurfaces.

By way of a summary account of practice of this invention in one of itsaspects, an elongated tubular resinimpregnated paper bobbin, such as onehaving a slight inward taper from bottom to top, has its generallysmooth exterior shaped, by a die, into a succession of adjacentslightly-conical steps or increments, each about one-fourth inch inlength and each preferably with a slight uniform taper inwardly from topto bottom (i.e., the step taper is of sense reversed from the overalltaper of the bobbin). The conical steps each exhibit a riser height, atthe site of meeting with an adjoining step, which is less than thecross-sectional diameter of the yarn intended to be wound upon thebobbin. Yarn entrapments and irregular lay-on during winding areunlikely, while at the same time the wraps of yarn tend to holdthemselves, and the resulting yarn package, against axial slippage,while falling into place in a controlled even manner during high-speedwinding; stripping of any waste remaining after unwinding isaccomplished readily and without undue hazard of damage to the bobbinsurfaces, because the yarn does not to lodge inaccessibly in recesses.

BRIEF DESCRIPTION OF THE DRAWING Although the features of this inventionwhich are considered to be novel are expressed by way of the appendedclaims, further details as to preferred practice of the invention, aswell as to further objects and ad vantages thereof, may be most readilycomprehended through reference to the following description taken inconnection with the accompanying drawings, wherein:

FIG. 1 provides a side view of an improved textile bobbin, inassembledrelation to a drive spindle, a yarn package being outlined by dashedlinework;

FIG. 2 represents an enlarged fragment of the bobbin of FIG. 1, togetherwith linework designating tapers, and cross-sectional yarn strands; and

FIG. 3 illustrates a cross-sectioned portion of a bobbin, such as thatof FIG. 1, together with scraping elements for waste removal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The assembly appearing in FIG.1 includes a spindle structure of a known type wherein a substantiallycylindrical upright spindle is rotated about a vertical axis 5 5 by wayof a whorl 6, on support bearings (not shown) carried upon the usualtextile machine spinning frame with which such spindles are commonlyassociated. Mated about the spindle, and rotated by it, in turn, throughcomplementary seating surfaces near the tip of the spindle, is alaminated resin-impregnated tubular paper bobbin 7, having metal endcaps 8 and 9. In all respects save those which have to do with theunique stepping of its outer surfaces, bobbin 7 is generally like thoseknown earlier, and is intended to have a package of yarn developed aboutit through controlled uniform-tension evenly-laid wrapping as the bobbinis rotated at high speed. Dashed linework l0 characterizes the outlineof a typical yarn package, for example.

When a textile bobbin is initially donned or dropped onto a spindle fora winding operation, it should be wholly free of waste remnants frompreceding windings, and should exhibit smooth non-snagging surfaces. Thefew turns of to-be-wound yarn which have earlier been wrapped about thebase or acorn portion 11 of the spindle provide a starting hold for yarnbeing taken from the usual overhead supply, and, as the spindle rotates,the yarn is fed onto its exterior surfaces through a conventionallightweight metal traveller loosely fitted onto a surrounding ring whichis alternately raised and lowered by the customarily-used mechanisms, tospread the wrap or lay of yarn onto the bobbin in a prescribed mannerwhich should regulate the build-up of the yarn package. Unless the yarnbeing wrapped next to the bobbin is free of entrapments, and is laidonly in the intended places as the winding progresses, it may at timesbe unduly tensed or slack, and will be more subject to the verytroublesome and costincreasing breakage or ends down conditions whichare so vexing to the industry. Heretofore, the smooth external surfacesof such bobbins have commonly been interrupted only by annular groovesor corrugations, into which certain of the turns of yarn should fall,with the objective of preventing axial slippage both of the pattern ofthe yarn sought to be wound and of the completed yarn package as awhole. However, because of the yarn tensions which can develop duringwinding, the yarn diameter can be reduced and more than one turn can bestressed tightly into such grooves, with the aforementioned untowardresults.

In offsetting such peculiar problems, the exterior of bobbin 7 isstepped in short shallow increments, such as 7a, 7b, 7c and 7d. Theillustrated bobbin is about ten inches in length; about one andone-eighth inches in outer diameter near the bottom, and has an overalltaper inwardly to about a 13/16 inch outer diameter near the top;although the exterior has the aforesaid stepped characteristic, theoverall bobbin taper, of about 0.025 inch per inch, is observed by thelocus of the front edges of the steps along the taper line .12-12. Eachof the steps, such as increments 7a 7d, is typically only about inch inlength, as is designated by dimension 13, because very significantlygreater lengths may not provide enough of a yarn-locating effect toassure a well-controlled winding and properlyshaped package. A lengthwhich enables the laying-on of about 50 or 60 turns of yarn perincrement appears to be quite satisfactory.

The FIG. 2 enlargement of a fragment of the same bobbin shows that eachstep, of circular cross-section, such as step 7c, has a substantiallysmooth surface following a substantially linear path, i.e., has asubstantially linear generatrix, such as 14-14. Taper of each step isillustrated as negative, in that it is of sense opposite to that of thetaper of the overall bobbin profile line l2l2, its angle 15 being aboutl.5 as initially formed by a suitable die. Corresponding maximum height16 of the riser 17 of each step is then about 0.013 inch, as initiallyformed. The slight negative taper is found to be appropriate when thickor only relatively-fine yarns (such as so-called 30s yarn) are to bewound; that is, each step is designed to be very slightly conical in asense opposite to that of the configuration of the bobbin as a whole.Alternatively, for such yarns, the generatrix for each step may besubstantially parallel to the longitudinal axis of the bobbin, with theresult that each step is of substantially rightcylindrical outline.Thinner or finer yarns, such as socalled 60s or s yarns, are betterprocessed using bobbins wherein the steps are frustro-conical and have aslightly positive slope of the same sense as the taper of the bobbinprofile.

The aforementioned 30s yarn, when uncompressed, has a cross-sectionaldiameter of about 0.007 inch, and, when under maximum tensions, exhibitsa much-reduced cross-section of about 0.003 inch. Optimum maximum depth,16, of the bobbin steps is not less than about half of the compressed orminimum diameter of tensed yarn which is to be wound upon it. Thatrelationship is illustrated for the yarn elements 18 I in FIG. 2, but itis nevertheless entirely feasible to use the same bobbin for much fineryarns with improvement in relation to operation involving prior-artgrooves. Such finer yarn is designated by reference character 19, andwill be seen to collect in orderly fashion upon the steps and theirriser portions 17. Importantly, the steps and their risers involve nosharp depressions or reverse curvatures inviting unwanted entrapments orsevere self-locking of the finer yarn, and even such yarn will tend tofree itself readily from the bobbin during unwinding or waste-strippingoperations. In the latter connection, the riser portions 17 aredieformed with smoothly blended contours, and their faces are whollypositively-sloped (i.e., sloped in direction the same as that of anyoverall taper of the bobbin, but at much steeper angles and are inexcess of acuteangle relationships with the step surfaces. Thesurfacesloping and dimensioning of the steps, imparted by a suitableforming disc or die, will tend to reduce somewhat as the bobbinmanufacture progresses, depending upon the bobbin material, resinimpregnation, and the heat of baking, and may be taken into account byway of slight initial exaggerations. The maximum springback depth ofeach step, after the steps have been formed to an initial depth 16 andthen reduced as the result of dimensional changes induced by subsequentprocessing in manufacture, is preferably but a few thousandths of aninch, such as 0.003 to 0.006 inch or In FIG. 3, part of a like bobbin isrepresented in association with waste-stripping blades or scrapers 20.When moved in the direction of bobbin taper, 21, toward the top of thebobbin, whether by manual or mechanized means, the scrapers will drivewaste remnants from the bobbin, without the application of undue forcewhich would quickly deteriorate the bobbin surfaces.

Practices here described may be employed with plastic or other bobbins,and to untapered bobbins or to those driven other than via internal topseating. Accordingly, it should be understood that the embodiment andpractices specifically described and portrayed have been presented byway of disclosure, rather than limitation, and that variousmodifications, substitutions and combinations may be effected by thoseskilled in the art without departure from the spirit and scope of thisinvention in its broader aspects and as set forth in the accompanyingclaims.

What is claimed is:

1. A bobbin for textile yarns and the like having an elongated bodyportion of substantially circular crosssectional outline for collectionand holding of a yarn package thereon, said body portion being ofresinimpregnated paper and about ten inches in length and having anouter diameter of about one and one-eighth inches near said bottom, theexterior of said body portion being of incrementally-steppedconfiguration longitudinally thereof and involving a plurality ofrelatively short-length steps in end-to-end relationship along all ofsaid body portion upon which yarns are intended to be wound, said bodyportion being tubular and following an inward taper in direction frombottom to top of said bobbin, said linear taper from bottom to top beingabout 0.025 inch per inch, the generatrix of each of said step surfacesbeing slightly sloped in relation to the longitudinal profile of saidbobbin and said step surfaces being sloped in direction opposite to thedirection of said taper, and the riser surfaces interconnectingadjoining ones of said step surfaces being relatively short and slopedin greater than acute-angle relationships to said step surfaces, theslope of said step surfaces being not in excess of a few degrees, thelength of each of said step surfaces being substantially onefourth inch,all the outer ends of said step surfaces being disposed along pathsdefining linear toward taper of said body portion from bottom to topthereof, and said riser surfaces being smoothly contoured ininterconnecting said step surfaces, all of the surfaces of said bodyportion being substantially smooth and uninterrupted except for saidstepped configuration, and the maximum height of said riser surfaces, indirection radially, of said bobbin, being of the order of a fewthousandths of an inch, whereby yarn entrapments on said bobbin exteriorare avoided, controlled even winding of yarn is promoted, and wasteremoval is facilitated by said stepped configuration.

1. A bobbin for textile yarns and the like having an elongated bodyportion of substantially circular cross-sectional outline for collectionand holding of a yarn package thereon, said body portion being ofresin-impregnated paper and about ten inches in length and having anouter diameter of about one and one-eighth inches near said bottom, theexterior of said body portion being of incrementally-steppedconfiguration longitudinally thereof and involving a plurality ofrelatively short-length steps in end-toend relationship along all ofsaid body portion upon which yarns are intended to be wound, said bodyportion being tubular and following an inward taper in direction frombottom to top of said bobbin, said linear taper from bottom to top beingabout 0.025 inch per inch, the generatrix of each of said step surfacesbeing slightly sloped in relation to the longitudinal profile of saidbobbin and said step surfaces being sloped in direction opposite to thedirection of said taper, and the riser surfaces interconnectingadjoining ones of said step surfaces being relatively short and slopedin greater than acute-angle relationships to said step surfaces, theslope of said step surfaces being not in excess of a few degrees, thelength of each of said step surfaces being substantially one-fourthinch, all the outer ends of said step surfaces being disposed alongpaths defining linear toward taper of said body portion from bottom totop thereof, and said riser surfaces being smoothly contoured ininterconnecting said step surfaces, all of the surfaces of said bodyportion being substantially smooth and uninterrupted except for saidstepped configuration, and the maximum height of said riser surfaces, indirection radially, of said bobbin, being of the order of a fewthousandths of an inch, whereby yarn entrapments on said bobbin exteriorare avoided, controlled even winding of yarn is promoted, and wasteremoval is facilitated by said stepped configuration.